This invention applies to rotary engines and more particularly to a system for utilizing on a selective basis all or a fraction of the rotors in a multiple rotor rotary engine for producing output power.
Numerous attempts have been made in the prior art to selectively split reciprocating engines so that, in response to the power demand on such an engine, all or a portion of the reciprocating cylinders are used to produce output power. A particularly efficient and successful modification for such a reciprocating engine is shown in my previously filed patent application Ser. No. 503,718, filed on Sept. 6, 1974, entitled APPARATUS FOR MODIFYING AN INTERNAL COMBUSTION ENGINE now U.S. Pat. No. 4,019,479. . Thus, the fundamental realization that, under differing load conditions, a multiple combustion chamber reciprocating engine can be operated most efficiently by altering the number of combustion chambers used to produce output power has been recognized for a period of time in the art. Different problems are encountered, however, in the use of engine splitting modifications for rotary engines, and particularly Wankel engines, and such have not been solved in the prior art.
Initially, rotary engines having multiple rotors in most cases will not idle satisfactorily unless all of the rotors are used to produce the power for idling. Thus, if only a portion of the rotors are supplied with fuel or air for combustion, the idling speed must be maintained at an excessive level, resulting in excessive wear on the engine and excessive fuel comsumption. If such an engine is adjusted to normal idling speeds, it will simply not operate.
It is known from my previous application in monitoring power demand from an engine for splitting the engine to monitor the vacuum in an intake manifold. Since the vacuum at idle is relatively high, such a monitoring system would normally require that only a portion of the multiple rotors be used for producing idling power. Thus, the prior art engine splitting modifications do not provide teachings which permit an efficient split rotary engine having normal idling characteristics.
The second significant problem in adapting prior art engine splitting techniques to rotary or Wankel engines is caused by the fact that rotary engines must be supplied, through the normal fuel intake manifold, a small quantity of oil to lubricate the apex seals on each of the rotors. The amount of oil supplied to the rotors in a rotary engine is normally controlled by the position of the carburetor throttle valve. Thus, throttle valve modifications used to split the engine would normally result in a failure to properly lubricate those rotors which are not being used at a particular time to produce output power, which would result in severe damage to the rotary engine.